Fixes issues mentioned in comments.

- [x] Highlight for selected date should be bold text.
- [x] Hover highlight for day should be the same as for the selected date.
- [x] Remove hover effect on the week.
- [x] Row for days of the week should indeed stay, but non-bold and at 50% opacity so it doesn't take away the focus.
- [x] Dates of previous and next months a bit lighter.
- [x] Remove marking the weekend blue.
- [x] The box centered below the date field, with triangle in the middle.

Signed-off-by: Marin Treselj <marin@pixelipo.com>